If you are starting to feel like the coronavirus epidemic will never end, then you may be correct. A statistical quirk in testing means that Britain may never hit zero cases, even if the virus is wiped out entirely.
The reason lies in the large number of false positives that are almost certain to creep in once case numbers drop very low, yet testing remains very high.
Testing is never 100 per cent accurate, and scientists must factor in the false positive and negative rates when determining infection prevalence. The problem is, nobody knows what those rates are.
The best guess at present is that coronavirus tests pick up around 80-85 per cent of positive cases, and around 99.9 per cent of negative cases.
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